In the field of meat processing, such as pork processing, it is well known that excess fat is removed from the back of the loin of a animal carcass to recover the loin before final cutting and/or packing the meat for market. Typically, the carcass of the animal is cut into two halves, and then cut transversely to remove the hind and fore quarters. The resulting portion is commonly referred to as the "middle" and will be referred to herein as the "carcass middle". Each carcass middle includes a loin to be removed from the back fat. The loin is adjacent to the back bone, or chine, and is situated between the ribs and the outer layer of fat.
Various automatic devices have been developed to provide for the separation of the loins from the carcass middle. Typical of the art is the device disclosed in U.S. Pat. No. 4,189,806 issued to W. P. Van Heyningen on Feb. 26, 1980 and Canadian Patent No. 1,079,114 issued on Jun. 10, 1980. Both of these disclose the same invention and, like other known devices at that time, required the carcass middle to be further subdivided prior to the removal of the loin.
A device for accomplishing the automatic removal of the loin from a full carcass middle is described in U.S. Pat. No. 5,234,371 owned by a common assignee of the present invention. A further device for accomplishing the automatic removal of the loin from a full carcass middle is disclosed in U.S. Pat. No. 5,395,898 also owned by a common assignee of the present invention. Additionally, U.S. Pat. No. 5,407,384, ("the '384 patent"), also owned by a common assignee to the present invention, discloses a further device for accomplishing the automatic removal of the loin from a full carcass middle. These devices are incorporated herein by reference for teachings regarding the general structure and operation of a "loin puller". It is an improvement over the device disclosed in the '384 patent that is described fully hereinafter.
The shortcoming of the known art, including that of the above cited U.S. Pat. No. 5,234,371, and the '384 patent, is that, as known in the art, the chine is naturally curved and the known devices do not include a means for straightening the chine as the carcass middle approaches and engages the loin knife. And, while the loin puller described in the '384 patent includes a guide plate at the edge of the work surface for positioning the carcass middle during its movement through the device, the known devices do not include means for insuring that the carcass middle is automatically aligned with the loin knife in reference to the positioning of the chine. Also, since the invention of the device disclosed in the '384 patent, it has been learned that the loin can be more uniformly pulled if the depth of the scribe saw cut can be limited. Finally, the known devices do not automatically detect when the carcass middle has reached the location of the scribe saw and are thus unable to automatically activate the downward motion of the scribe saw for engagement with the carcass middle.
Accordingly, it is an object of the present invention to provide a guide bar for guiding the carcass middle into the loin puller and to provide a load bar that engages the chine in order to uniformly align the carcass middle with the loin knife.
A further object is to provide a means for pressing the chine against the load bar as the carcass middle travels through the loin puller so as to substantially straighten the chine before the carcass middle engages the scribe saw and the loin knife.
Still another object of the present invention is to provide for a means of decelerating the downward movement of the blade of the scribe saw and to limit the depth of the cut of the scribe saw.
Yet another object of the present invention is to provide automatic engagement and disengagement of the scribe saw with the ribs of the carcass middle.
Other objects and advantages over the prior art will become apparent to those skilled in the art upon reading the detailed description together with the drawings as described as follows.